Mechanical time fuse for artillery projectiles



June 27, 1933. JUNGHANS 1,915,890

MECHANICAL TIME FUSE FOR ARTILLERY PROJECTILES Filed July 30, 1931 2Sheets-Sheet 1 flffarwey June 27, 1933. 4 H. JUNGHANS 1,915,390

MECHANICAL TIME FUSE FOR ARIILLERY PROJECTILES Filed July so, 1931 2Sheets-Sheet 2 .1 2 4 H [five-77:01"; eZmuZ tfung'zzaws M W ALZoz-neyPatented June 27, 1933 UNITED STATES PATENT OFFICE HELMUT JUNGHANS, 0FSCHRAMBERG, GERMANY, ASSIGNOR TO SOCIETA ANONIMA. ARTURO J UNGHAN SFABRICA DOROLOGERIA, OF VENICE, ITALY MECHANICAL THEE FUSE FOR ARTILLERYPROJECTTLES Application filed July 30, 1931, Serial No. 554,101, and inGermany August 15, 1930.

The present invention relates to mechanical time fuses for artilleryprojectiles and more particularly to a time fuse of the stated kindwherein the necessary moments of force are obtained exclusively by meansof centrifugal weights.

In fuses of this type as hitherto constructed the driving toothedsegments or racks are adapted to mesh directly with a pinion keyed to orintegral with the central shaft of the fuse,said shaft carrying theusual'setting disk and being arranged to perform a single revolutiononly during the most prolonged trajectory or flight of the projectile,whereas according to the present invention, a means for transmissionfrom a lower to a higher speed is interposed between the said segmentsand the central shaft, said means comprising a system or set of toothedwheels.

The provision of such a transmission means between the driving segmentsloaded with centrifugal weights,and the central shaft of the fuseentails a marked advantage over the time fuses of this type as hithertoconstructed or suggested, inasmuch as the said'centrifugal weights willhave to travel a path of minimal length only in order to cause thecentral shaft to move and perform a full revolution. In

this way the difference in the positions of thetance between thecentrifugal weights and the rotation axis.

Thus the reduction of the path or travel of the segments will act toobviate and decrease the unevenness or disproportionof thedrivconnection with the accompanying drawings, forming a part of thisspecification and showing somewhat diagrammatically for purposes ofexemplification, a preferred form and manner in which the invention maybe embodied and practised, but without limiting the claimed invention tosuch illustrative instance:

Figure 1 is a rear view partly in section of the fuse, and

Figs. 2 to 5 are graphic representations indicating the calculations ofthe centrifugal forces.

The two centrifugal weights a are firmly attached to toothed segments apivotally mounted on supporting studs 6 so as to be adapted to turnthereabout. The two segments a engage in pinions c firmly connected orintegrally formed with toothed wheels d constituting the means fortransmission from a lower to a higher speed, between the segments a andthe central shaft e, the arrangement being such that both wheels elengage at diametrical points in a pinion keyed to or integral with theshaft e and adapted to actuate in a known manner both the setting diskand regulating means of the fuse;

Figures 2 to 5 of the drawings illustrate graphically two calculationsof the driving centrifugal forces, Figure 2 showing the calculation ofthe driving centrifugal forces of: the prior construction, wherein thesegment immediately engages in the pinion of the central shaft. In thiscase the weight ap-- pended to the segment will travel a path of 10 mmlength at or for a full revolution ofthe central shaft. V Apart from thecentrifugal forces acting upon the weight of the segment, the tangentialforces are plotted and converted to the pitch circle of the pinion ofthe central shaft Figure 4 is a diagram showing the said tangentialforces in the form of a curve. It will be seen therefrom, that the forceat the beginning of the movement bears a proportion of 1 to 3, 4 to theforce exerted at the end of the movement.

Figure 3 illustrates the same graphical calculation or lottingrespecting the construction of the filse according to the presentinjectile decreases durin vention, wherein the segments do notimmediatel mesh with the pinion of the central shaft ut rather engage ina separate pinion formed integral with a toothed wheel meshing with thepinion of the shaft. In this way, that is due to the transmission. meansprovided in my fuse, the movement or travel of the weights will amountto 3, 5 min. only, while the movement of the central shaft, that is onerevolution in case of a most prolonged flight or trajectory, will be thesame. In Figure 3 the tangential forces at the center of gravity of thesegment like'wise are plotted from the centrifugal forces by divisionand the said forces are correlated to the pitch circle of the pinion ofthe central shaft with consideration of the transmission efiected inthis case. L

The tangential forces are similarly shown in Figure 5 in the form of adiagram from which will be seen that the force at the commencement ofthe movement bears a relation of 3 to 4 to the force prevailin at theend' of the movement. Smce, as ereinbefore mentioned, the rotating speedof the prothe flight approximately in the same ratio, an approximatelyuniform driving force is likely to prevail at such a. proportion orcondition of the forces during the entire flight or trajectory.

From the foregoing it is believed, that the advanta es and novelfeatures of my invention wil be readily understood, and, therefore,further detail description is deemed unnecessary. I desire, however, toemphasize the fact that various minor. changes in I the details ofconstruction and in the proportion of parts may be resorted to whenrequired, without sacrificing any of the advantages of my invention asdefined in thehaving a setting disk, comprising two pivotally mountedtoothed segments, centrifugal weights associated with the said segments,a central shaft, a pinion keyed to the shaft, 21

pair of spur gears meshing with the said pinion, and a pair of pinionsassociated with the said two spur gears, respectively, and engaging inthe said two segments, respectively.

In testimony whereof'I aflix my signature.

HELMUT JUNGHANS.

